Brunswick County Commissioners vote to build RO plant

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Brunswick County leaders and state lawmakers saw first hand the work of a pilot RO system at the Northwest Water Treatment Plant. (Photo: WWAY)

BRUNSWICK COUNTY, NC (WWAY) — Brunswick County’s Commissioners voted unanimously to approve construction of a low-pressure reverse osmosis plant at the Board’s budget workshop Thursday.

On April 16, the board received a report from CDM Smith, the firm hired to research and review data, conduct pilot tests and consult with experts regarding advanced water treatment methods and the presence of chemicals in the Cape Fear River, from which Brunswick County draws water. CDM Smith recommended low-pressure reverse osmosis (LPRO) as the most efficient and cost effective advanced water treatment addition to the Northwest Water Treatment Plant.

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After hearing the recommendation made, the commissioners and county staff reviewed CDM Smith’s report and findings, along with information about the effectiveness and cost of other treatment methods. After reviewing and researching, County staff also recommended LPRO, and the Board of Commissioners voted Thursday to move forward with implementation of LPRO as the most cost effective long-term solution for Brunswick County water treatment.

According to a news release, the report from CDM Smith showed that the pilot LPRO system set up at the Northwest Water Treatment Plant removed 45 PFAS compounds to as close to non-detectable limits as possible. In one round of testing, all 45 PFAS compounds were removed to non-detectable levels; in a second round of testing, 44 of 45 PFAS compounds were removed to non-detectable levels. In the testing results, the total sum of 45 perflourinated chemicals was 11 nanograms per liter. All but one of the perflourinated chemicals were not detected in the treated water using the best technology currently available, representatives from CDM Smith told the Commissioners.

Testing was completed to determine the presence and amount of more than 45 compounds, including GenX, Nafion Byproduct 1 and Nafion Byproduct 2, Perflourooctanesulfonic acid (PFOS), Perflourooctanoic acid (PFOA), 1,4-Dioxane and PFMOAA in the water before and after treatment by the LPRO unit. The testing results also showed a 94-percent removal of 1,4-Dioxane, taking it from 3.2 µg/L before the LPRO treatment to 0.2 µg/L after treatment. Other substances, including the insect repellant DEET, the herbicide Atrazine, and the seizure medicine Carbamazepine were not detected in the LPRO-treated water.

In recommending LPRO, CDM Smith noted that its operational and maintenance costs are less than other methods that would require frequent changing of filtration material, and that using LPRO after the County’s current filtration methods would cost less than a higher-pressure system that would be needed to treat brackish groundwater.

Implementation of LPRO is estimated to cost approximately $99 million, with additional operations and maintenance costs of approximately $2.9 million per year.

“The net present worth, the life cycle cost if you will, of reverse osmosis is almost half of the other [treatment methods and method combinations considered],” Bill Dowbiggin, Senior Vice President and Senior Environmental Engineer with CDM Smith, told the Commissioners in April.

The release said preliminary design work has begun, with final design work expected to begin in September. The application process for NCDEQ to modify the County’s existing discharge permit began in February, and has proceeded with no “red flags” from regulators. Bidding and construction of the project is expected to begin in June 2019.

Brunswick County said they had previously planned to expand the capacity of the Northwest Water Treatment Plant to meet the demand, prior to the discovery of GenX in the Cape Fear River. These expansion plans remain in place, and the proposal for LPRO includes plans to accommodate that increase in capacity.

The country say this  approach allows them to take advantage of economies of scale associated with the construction costs of additional water treatment methods.

Brunswick County has also evaluated treatment options that are effective on a number of chemicals found in the Cape Fear River, including some only recently discovered.

Here is the statement from the Town of Belville reacting to Brunswick County’s RO decision today:

Here is the statement from the Town of Belville reacting to Brunswick County’s RO decision today:

“With today’s action, Brunswick County just confirmed that the cheapest, fastest way to deliver the cleanest water to H2GO’s customers is to build Belville’s RO plant. This is not Brunswick County’s fault; the county didn’t plan for GenX and other chemicals to be found in the Cape Fear River. They could not anticipate the estimated 25% rate increase. However, H2GO’s customers will be able to have cleaner water drawn from chemical-free aquifers in less than a year with the Belville plant.  And the plant will not increase rates because of seven years of proper financial planning. It’s time to bring safer, cleaner water faster AND cheaper to the 25,000 people H2GO serves. It’s time to finish the Belville RO plant.”